It is an object of the present invention to provide a separator which can improve the valve regulated lead-acid battery both in the pressure lowering prevention effect and the electrolyte stratification prevention effect, and a valve regulated lead-acid battery using the same.The separator for the valve regulated lead-acid battery of the invention is a separator for a valve regulated lead-acid battery, comprising a paper sheet manufactured by a wet papermaking process mainly made of fine glass fibers, which is characterized in that the separator is a structure in which a thin fiber layer comprising glass fibers having an average fiber diameter of 0.5 to 0.8 μm as the fine glass fibers and a thick fiber layer comprising glass fibers having an average fiber diameter of 1.3 to 1.9 μm as the fine glass fibers are laminated in the thicknesswise direction of the separator so that the one thick fiber layer is covered with the two thin fiber layers from both sides to constitute a three-layer laminated structure, wherein the average fiber diameter of the glass fibers in the all layers is 1.1 μm or more, wherein the thickness ratio of the thin fiber layers to the thick fiber layer in the all layers is 25/75 to 50/50.